Firearm safety device



March 24, 1953 F, HOLEK 2,632,272

FIREARM SAFETY DEVICE Filed April 27, 1950 Patented Mar. 24, 1953 U N I T E D TT E ENT OFFICE rmEARM SAFETY DEVICE Application April 27, 1950, Serial No. 158,421 In Czechoslovakia April 29, 1949 9 Claims.

This invention relates to a safety device for a nre arm of the type wherein barrels are frequently changed or removed, and more particularly to an arrangement in which the insertion of the magazine is blocked unless the barrel is properly locked in place. Hitherto, lire arms have had the disadvantage of permitting the insertion of the magazine even though the barrel is not properly locked in place whereby the re arm may be unintentionally discharged by rotation of the barrel either from firing shocks or from other causes. Such firing may damage or completely ruin the fire arm as Well as cause personnel casualty.

This serious disadvantage is overcome according to the instant invention by providing the barrel coupling sleeve and the adjacent part of the breech block casing with cooperating members movable in dependence upon the position of the coupling sleeve in such a Way as to permit the magazine of the re arm to be inserted into the receiver thereof only when the barrel is completely locked in place.

By way of example, an embodiment of the invention is shown in the accompanying drawing wherein like parts are designated by like reference characters and in which:

Fig. 1 is a partial longitudinal section of a re arm showing the barrel coupling sleeve in locked position;

Fig. 2 is a view similar to Fig. 1 but showing the barrel coupling sleeve unlocked;

Fig. 3 is an end vievir of the barrel locking sleeve; and

Fig. 4 is a plan View of the barrel locking sleeve.

The barrel of the iire arm, which in the case to be described may be considered to be the barrel of a magazine fed machine gun, is removably placed in the casing 2 of the breech block and secured in operative position by a barrel coupling sleeve 3 movably or rotatably mounted on the breech block casing. The coupling sleeve 3 is provided with conventional threads li interrupted by longitudinally extending cross cuts 5, the shape and arrangement of which are identical with longitudinal thread segments on the rear end of the barrel I. To unlock the barrel, the sleeve 3 is rotated by arm 6.

In the upper part of the breech block casing 2 a receiver l is formed, vthe front Wall of which is provided with a depression 8 for receiving a cam-like projection 3 on the front wall of the magazine IG. IIhe magazine is further secured in operative position by a spring urged detent member II positioned in the rear portion of the diminuait. l

receiver I for engagement with another projection on the rear wall of the magazine I0. The reference character I2 indicates generally the breech block support governing the function ci the re arm and has no particular function relative to the invention itself.

In order to prevent the loading of the fire arm and/or the insertion oi the magazine I0 into the receiver l, when the barrel I is not in place and when the coupling sleeve 3 is loose or unlocked, the construction of parts is arranged so that the barrel coupling sleeve 3 and the adjacent part of the breech block casing are provided with cooperating members movable in dependence upon the position of the coupling sleeve in a manner such as to permit the magazine I0 to be inserted into the re arm only when the coupling sleeve 3 is in completely locked position. These members comprise a governing member formed in the barrel coupling sleeve 3 and a cooperating member which can be moved into the receiver l to block the insertion of a magazine I0 by the rotation of the governing member. In the case considered, the governing member comprises a bent or curved groove I3 in the rear wall of the barrel coupling sleeve 3. Groove I3 is formed with the sleeve preferably in such a manner that the position of its beginning and its end cover the extreme positions of movement, that is the locking and unlocking positions of the coupling sleeve. This means that the groove I3 is of a length equal to the movement of the operating arm 6 of the coupling sleeve from the solidly indicated fully locked position to the dotted unlocked position, both particularly shown in Fig. 3. The groove I3 is not of constant depth throughout its length but is formed so that its depth progresses from the beginning of the groove Whereat it is slight gradually toward the end of the groove in a vertical plane through the sleeve 3 Whereat it reaches a maximum. The profile of the bottom of the groove can be straight or suitably curved as, for example, a helical or screw shape.

Cooperating with the groove I3 is a longitudinally slidable member or pin I5 slidably positioned in a guiding bore in the breech block casing 2 and intermediate the ends of which is an enlarged aperture Ifl containing a spring surrounding the pin I5 and positioned between a wall or shoulder of said aperture and a suitable abutment secured to the pin I5. The pin is thereby positioned in the breech block casing 2 opposite the end of the curved groove I3. This slidable member or pin I5 may be formed in various manners but in the embodimentI shown in the drawing it is shown as a straight pin l urged under the pressure of spring I6 in engagement with the bottom of the curved groove I3 of the barrel coupling sleeve 3. The length of the pin I5 is such that the pin in the locked position of coupling sleeve 3 is urged into the deep end of said groove and within its guiding bore so that the opposite end does not project into the receiver 1.

The pin l5 in this normal or locked position does not project into the depression 8 for the cam 9 of the magazine and this permits the magazine and cam to be readily inserted into the receiver 1. If, however, for any reason the barrel coupling sleeve 3 is unlocked or rotated, the sloping bottom of the groove I3 urges the pin l5 rearwardly into the depression 8 and ultimately into the receiver itself, thereby blocking the insertion of a magazine thereinto and warning the operator or gunner to duly lock the barrel coupling sleeve and barrel in place before being able to insert the magazine in preparation for firing.

The safety members, it is to be understood, are not at all limited to the example specied and therefore, can be constructed in other ways without departing from the true spirit and scope of the invention. For example, it is perceived that the groove on the coupling sleeve may be replaced by a proled projection and the movable safety member arranged as a system of piston rods or levers. The invention also is not limited to fire arms in which the combustion gases are taken off through the barrel but can also be used for fully automatic fire arms. Thus it is intended that the invention can be adapted to use with fire arms fed with ammunition from a cartridge belt, the safety member merely blocking further feed of ammunition thereinto.

Having complied with the statute by particularly describing what is at present believed to be a preferred embodiment of the invention, what is claimed and desired to be protected by the issuance of Letters Patent of the United States is:

1. In a re arm, a barrel, a breech block casing, a rotatable coupling sleeve adapted to couple and uncouple said barrel to and from said breech block casing, a receiver formed in said breech block casing, a safety member movably mounted in said breech block casing between said receiver and said rotatable coupling sleeve, and means carried by said coupling sleeve for moving said member into said receiver upon rotation of said coupling sleeve. 2. In a fire arm, a barrel, a breech block casing, a rotatable coupling sleeve adapted to couple and uncouple said barrel to and from-said breech block casing, a receiver formed in said breech block casing, a pin slidably mounted in said breech block casing between said receiver and said coupling sleeve, and means carried by said coupling sleeve for moving said pin into said receiver upon rotation of said coupling sleeve.'

3. In a fire arm, a barrel, a breech block casing, a rotatable coupling sleeve adapted to couple and uncouple said barrel to and from said breech block casing, said coupling sleeve having a locked position determining one limit of its rotation, a receiver formed in said breech block casing, a pin slidably mounted in said breech block casing between said receiver and said rotatable coupling sleeve, resilient means within said breech block casing for urging said pin toward said coupling sleeve, and means carried by said coupling sleeve for moving said pin against the tension of said resilient means into said receiver upon rotation of said coupling sleeve from its locked position.

4. In a fire arm, a barrel, a breech block casing, a rotatable coupling sleeve adapted to couple and uncouple said barrel to and from said breech block casing, said coupling sleeve having a locked position determining one limit of rotation, a receiver formed in said breech block casing, a pin movably mounted in said breech block casing between said receiver and said rotatable coupling sleeve, said coupling sleeve in the end adjacent said breech block casing having formed therein a groove of gradually increasing depth,

I spring means carried within said breech block casing urging said pin into the deep end of said groove when said coupling sleeve is in locked position, the pin being of such length that the opposite end of said pin is thereby retracted out of said receiver.

5. In a re arm, a barrel, a breech block casing, a coupling sleeve rotatable between a locked and unlocked position and adapted to couple and uncouple said barrel to and from said breech block casing, a receiver formed in said breech block casing, said breech block casing having a depression therein adjacent said receiver, a cartridge Vmagazine provided with a front wall and a rear wall, a cam-like projection upon the front wall of said magazine for insertion into said breech block casing depression, a guide bore in said breech block casing extending between said depression and said coupling sleeve, a pin slidably mounted in said guide bore, a groove of increasing depth in said coupling sleeve adjacent said guide bore, a compression spring within said breech block .casing normally urging said pin into the deep end of said groove when said coupling sleeve is in locked position, said pin being of a length equal to the length of said guide bore plus the depth at the deep end of said groove, the opposite end of said pin being thereby retracted within said breech block casing and out of said receiver and depression so that said magazine and cam projection thereon may be freely inserted into said receiver and depression respectively, the bottom of said groove sliding said pin against the compression of said compression spring so that said opposite end moves into said depression and receiver as said coupling sleeve is rotated to its unlocked position, said pin thereby blocking the entrance of said magar zine and said cam projection thereon into said receiver and depression respectively.

6. In a first arm as set forth in claim 5, in which said groove in said coupling sleeve is curved.

7. In a re arm as set forth in claim 5, including another projection on the rear wall of said magazine, and spring urged detent means positioned at the rear end of said receiver for cooperation therewith to hold said magazine in place when said pin is retracted from said receiver and depression adjacent thereto.

8. In a re arm as set forth in claim 6, in which said coupling sleeve and barrel are provided with transverse threads, interrupted by cross cuts on the coupling sleeve and corresponding longitudinal threads on the barrel, whereby the barrel may be slid into place and locked therein by rotation of said coupling sleeve, an operating arm being provided for rotating said coupling sleeve.

6 REFERENCES CITED The following references are of record in the file of this Ipatent:

UNITED STATES PATENTS Number Name Date Kewish Dec. 25, 1928 Moore Dec. 3, 1929 

